linux-kernel - [v3 8/9] powerpc: teach platforms not to zero struct pages memory

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Date:   Fri,  5 May 2017 13:03:15 -0400
From:   Pavel Tatashin <pasha.tatashin@...cle.com>
To:     linux-kernel@...r.kernel.org, sparclinux@...r.kernel.org,
        linux-mm@...ck.org, linuxppc-dev@...ts.ozlabs.org,
        linux-s390@...r.kernel.org, borntraeger@...ibm.com,
        heiko.carstens@...ibm.com, davem@...emloft.net
Subject: [v3 8/9] powerpc: teach platforms not to zero struct pages memory

If we are using deferred struct page initialization feature, most of
"struct page"es are getting initialized after other CPUs are started, and
hence we are benefiting from doing this job in parallel. However, we are
still zeroing all the memory that is allocated for "struct pages" using the
boot CPU.  This patch solves this problem, by deferring zeroing "struct
pages" to only when they are initialized on PowerPC platforms.

Signed-off-by: Pavel Tatashin <pasha.tatashin@...cle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@...cle.com>
---
 arch/powerpc/mm/init_64.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index d42c6b3..c381bd7 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -181,7 +181,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
 		if (vmemmap_populated(start, page_size))
 			continue;
 
-		p = vmemmap_alloc_block(page_size, node, true);
+		p = vmemmap_alloc_block(page_size, node, VMEMMAP_ZERO);
 		if (!p)
 			return -ENOMEM;
 
-- 
1.7.1